| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |
| #define _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |
| |
| #include <__config> |
| #include <__type_traits/is_integral.h> |
| #include <cstddef> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <size_t...> struct __tuple_indices; |
| |
| template <class _IdxType, _IdxType... _Values> |
| struct __integer_sequence { |
| template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType> |
| using __convert = _ToIndexSeq<_ToIndexType, _Values...>; |
| |
| template <size_t _Sp> |
| using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>; |
| }; |
| |
| #if !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE) |
| |
| namespace __detail { |
| |
| template<typename _Tp, size_t ..._Extra> struct __repeat; |
| template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> { |
| typedef _LIBCPP_NODEBUG __integer_sequence<_Tp, |
| _Np..., |
| sizeof...(_Np) + _Np..., |
| 2 * sizeof...(_Np) + _Np..., |
| 3 * sizeof...(_Np) + _Np..., |
| 4 * sizeof...(_Np) + _Np..., |
| 5 * sizeof...(_Np) + _Np..., |
| 6 * sizeof...(_Np) + _Np..., |
| 7 * sizeof...(_Np) + _Np..., |
| _Extra...> type; |
| }; |
| |
| template<size_t _Np> struct __parity; |
| template<size_t _Np> struct __make : __parity<_Np % 8>::template __pmake<_Np> {}; |
| |
| template<> struct __make<0> { typedef __integer_sequence<size_t> type; }; |
| template<> struct __make<1> { typedef __integer_sequence<size_t, 0> type; }; |
| template<> struct __make<2> { typedef __integer_sequence<size_t, 0, 1> type; }; |
| template<> struct __make<3> { typedef __integer_sequence<size_t, 0, 1, 2> type; }; |
| template<> struct __make<4> { typedef __integer_sequence<size_t, 0, 1, 2, 3> type; }; |
| template<> struct __make<5> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4> type; }; |
| template<> struct __make<6> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5> type; }; |
| template<> struct __make<7> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5, 6> type; }; |
| |
| template<> struct __parity<0> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type> {}; }; |
| template<> struct __parity<1> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 1> {}; }; |
| template<> struct __parity<2> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 2, _Np - 1> {}; }; |
| template<> struct __parity<3> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 3, _Np - 2, _Np - 1> {}; }; |
| template<> struct __parity<4> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; }; |
| template<> struct __parity<5> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; }; |
| template<> struct __parity<6> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; }; |
| template<> struct __parity<7> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 7, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; }; |
| |
| } // namespace detail |
| |
| #endif |
| |
| #if __has_builtin(__make_integer_seq) |
| template <size_t _Ep, size_t _Sp> |
| using __make_indices_imp = |
| typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template |
| __to_tuple_indices<_Sp>; |
| #else |
| template <size_t _Ep, size_t _Sp> |
| using __make_indices_imp = |
| typename __detail::__make<_Ep - _Sp>::type::template __to_tuple_indices<_Sp>; |
| |
| #endif |
| |
| #if _LIBCPP_STD_VER >= 14 |
| |
| template<class _Tp, _Tp... _Ip> |
| struct _LIBCPP_TEMPLATE_VIS integer_sequence |
| { |
| typedef _Tp value_type; |
| static_assert( is_integral<_Tp>::value, |
| "std::integer_sequence can only be instantiated with an integral type" ); |
| static |
| _LIBCPP_INLINE_VISIBILITY |
| constexpr |
| size_t |
| size() noexcept { return sizeof...(_Ip); } |
| }; |
| |
| template<size_t... _Ip> |
| using index_sequence = integer_sequence<size_t, _Ip...>; |
| |
| #if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE) |
| |
| template <class _Tp, _Tp _Ep> |
| using __make_integer_sequence _LIBCPP_NODEBUG = __make_integer_seq<integer_sequence, _Tp, _Ep>; |
| |
| #else |
| |
| template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked _LIBCPP_NODEBUG = |
| typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>; |
| |
| template <class _Tp, _Tp _Ep> |
| struct __make_integer_sequence_checked |
| { |
| static_assert(is_integral<_Tp>::value, |
| "std::make_integer_sequence can only be instantiated with an integral type" ); |
| static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length"); |
| // Workaround GCC bug by preventing bad installations when 0 <= _Ep |
| // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929 |
| typedef _LIBCPP_NODEBUG __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type; |
| }; |
| |
| template <class _Tp, _Tp _Ep> |
| using __make_integer_sequence _LIBCPP_NODEBUG = typename __make_integer_sequence_checked<_Tp, _Ep>::type; |
| |
| #endif |
| |
| template<class _Tp, _Tp _Np> |
| using make_integer_sequence = __make_integer_sequence<_Tp, _Np>; |
| |
| template<size_t _Np> |
| using make_index_sequence = make_integer_sequence<size_t, _Np>; |
| |
| template<class... _Tp> |
| using index_sequence_for = make_index_sequence<sizeof...(_Tp)>; |
| |
| # if _LIBCPP_STD_VER >= 20 |
| // Executes __func for every element in an index_sequence. |
| template <size_t... _Index, class _Function> |
| _LIBCPP_HIDE_FROM_ABI constexpr void __for_each_index_sequence(index_sequence<_Index...>, _Function __func) { |
| (__func.template operator()<_Index>(), ...); |
| } |
| # endif // _LIBCPP_STD_VER >= 20 |
| |
| #endif // _LIBCPP_STD_VER >= 14 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |